In the field of microwave transmission, various researches and developments have been conducted. For example, beam control techniques using an active phased array antenna (APAA) and efficient transmission techniques have been in research and development, aiming at putting solar power satellites (SPS) into practice.
Further, efforts have been made to apply microwave transmission techniques to industrial applications. For example, patent literatures 1 and 2 disclose a steel manufacturing system that manufactures molten pig iron by irradiating a raw material with a microwave and heating this raw material. Further, nonpatent literatures 1 and 2 disclose techniques for using a phased array antenna as a microwave radiation source in a steel manufacturing system that uses the microwave. Furthermore, a technique for reducing the time required for chemical reaction by applying the microwave to chemical reaction has received attention recently.
The microwave transmission technique is applied to small-scale devices in many cases at the present time, though there is a demand for development of large-scale and large-electric-power devices such as steel manufacturing systems.